BPN849: Large-Amplitude PZT PMUTs

Project ID

BPN849

Website

Start Date

Tue 2016-Aug-30 15:46:30

Last Updated

Fri 2018-Jan-26 16:30:47

Abstract

Ultrasonic transducers are widely used in various applications including medical
imaging, nondestructive evaluation, object/gesture recognition, automotive, and range-finding.
Compared to conventional capacitive micromachined ultrasonic transducers (CMUTs),
piezoelectric micromachined ultrasonic transducers (PMUTs) have an advantage that they can be
utilized without high bias voltages, resulting in simpler electronic interfaces. This project
targets air-coupled PMUTs with wide bandwidth to achieve high axial resolution in pulse-echo
imaging, where air-coupled transducers typically operate in the frequency range of 40 kHz to
800 kHz. Regarding the piezoelectric material, the thin-film PZT (lead-zirconate-titanate) is
widely used for piezoelectric devices and well-known to have higher piezoelectric coefficient
e31,f as well as higher transmitting efficiency than those of another major piezoelectric
material AlN. In this project, we design, model, and characterize PZT PMUTs with a large
displacement amplitude for in-air operation to improve the sensor performance in pulse-echo
imaging system.